Structure and acid-basic properties of the surface of titanium oxides modified by phosphorus and aluminum and prepared by the alkoxo method. 2. Study of the active surface of titanium oxides

The data of temperature-programmed desorption of ammonia from the surface of oxide systems and IR spectroscopy were used to demonstrate that the strength of the surface acid sites in titanium oxides prepared by the alkoxo method and modified by aluminum decreases with respect to that in nonmodified titanium oxide. Modification of titanium oxide with P³⁺ ions from ethriol phosphite almost completely suppresses the acid properties. Modified oxides are able to chemisorb water. XANES data suggest that modification of titanium oxide with phosphorus ions increases the electron density on the titanium atoms and, correspondingly, the basicity of the materials.     

Determination of warfarin by sensitized fluorescence using organized media

The effect of surfactant micelles and albumin on the fluorescence warfarin of and the fluorescence of Eu³⁺ and Tb³⁺ sensitized by warfarin and the second ligand is studied. It was shown that sensitized fluorescence in the system Eu³⁺-tenoyltrifluoroacetone-warfarin allows a 3800-fold reduction of the detection limit for warfarin. The developed procedure was used to determine warfarin in soil.     

多功能两亲梳状聚合物的合成及包覆荧光量子点

利用溶液聚合和成酰胺反应合成了多功能梳状两亲性共聚物,聚(甲基丙烯酸-co-甲基丙烯酸十八酯)-(乙醇胺-乙二胺叶酸)(PSM-EE-FA).用红外光谱(FTIR),核磁共振(1H-NMR)及凝胶渗透色谱(GPC)表征了该聚合物的结构及分子量分布.实验结果证明合成了该聚合物,其数均分子量(Mn)为28600,多分散性为1.375.用该两亲梳状聚合物包覆油溶性CdSe/ZnS量子点,通过相转移作用,得到水溶性靶向量子点(PSM-EE-FA-QDs).该水溶性量子点溶液具有较好的稳定性.通过紫外-可见(UV-Vis)及荧光发射光谱分析对该量子点的光学性质进行研究.结果表明,PSM-EE-FA-QDs的紫外-可见光谱及荧光发射光谱峰形与原量子点基本一致.由于量子点表面聚合物层的形成,峰位发生少量红移.该量子点水溶液的荧光强度是原量子点氯仿溶液的98%,荧光产率是原量子点氯仿溶液的95%.动态光散射(DLS)及透射电镜(TEM)测试结果表明水溶性量子点分布均匀.合成的水溶性量子点不但光学性能稳定,而且聚合物及水溶性量子点的合成方法较为简便.     

相对论性核碰撞中Φ介子产生和弦碎裂函数

用强子和弦级联模型LUCIAE系统研究从AGS到SPS,到RHIC,再到LHC能量核–核碰撞中Φ介子产生.采用与能量有关弦碎裂函数,并通过与荷电粒子多重数实验数据的比较确定其中的参数后,LUCIAE模型给出的Φ介子产额与实验数据也都相近,得到的事件平均弦碎裂变量随能量之增趋饱和规律,可能是核穿透性能量行为的定性表示.     

以LCD为目标的自动定焦判据选择

在光学综合自动测量中 ,使用液晶显示屏作为分划板可以大大简化结构 ,提高效率 ,真正地实现自动测量。由于液晶显示具有对比度低、噪声大等特点 ,所以根据液晶的这些特点以及图像处理和CCD信号接收的特点选择两种适用的判据进行了分析和试验比较 ,并给出了结果。结果表明 ,这两种判别函数都适用于以液晶显示屏为目标和用图像处理方法进行光学参数测量的系统 ,其中锐度判别函数更优于信息熵判别函数 ,前者具有更好的抗干扰性和稳定性 ,而且其判定结果更接近目视清晰度判别     

Phase separation in high-T c superconductors, copper oxides, and related antiferromagnetic phases CuO and Y2BaCuO5

The acoustic properties and crystal structure of high-T _c superconducting cuprates and the related antiferromagnetic phases CuO and Y₂BaCuO₅ exhibit similar properties at a temperature of about 160 K and 240 K. These properties can be associated with the formation of inhomogeneous state of phase separation. Analysis of the magnetic properties of Y₂BaCuO₅ shows that these effects are of a nonmagnetic nature. The results of EXAFS data for the high-T _c superconducting compound Hg_0.8Tl_0.2Ba₂Ca₂Cu₃O_8.10 show that the phenomenon of phase separation is suppressed by superconductivity.     

Revêtements modérés et groupe fondamenttal de graphe de groupes

Let R be a discrete complete valuation ring, with algebraically closedresidue field. Let X be a semi-stable R-curve, with smooth generic fibre. In this paper we study tame coverings of X.     

Thermodynamic properties of furan-2-carboxylic and 3-(2-furyl)-2-propenoic acids

The standard enthalpies of combustion, formation, fusion, and sublimation of crystalline furan-2-carboxylic and 3-(2-furyl)-2-propenoic acids are determined by experimental methods and recalculated to 298 K. The possibility of using additive calculation schemes based on the principle of group contributions to calculate the standard enthalpies of vaporization and formation of substances with similar combinations of functional fragments in the gas phase is analyzed.     

Hydrocarbon specificity in the selective catalytic reduction of NOx over Cu-ZSM-5 and Co-ZSM-5 catalysts

Transformation of surface nitrates under CH₄ (CH₄+O₂) was found to ensure steady-state activity of Co-ZSM-5 in the selective catalytic reduction of nitrogen oxides by methane (CH₄-SCR). For Cu-ZSM-5, such species are mainly converted into NO. Relaxation of the coordination sphere due to oxygen and NO adsorption, stability of C,N-containing intermediates and activation routes of hydrocarbons (methane, propane) were analyzed as factors determining catalytic properties of Cu and Co cations.